Enabling means for a paper cutter in a facsimile system

ABSTRACT

Apparatus for severing recording medium in a document reproduction system, such as facsimile, wherein the transmitter produces an enabling signal indicating that a document has been inserted for reproduction and the detection of the signal at the receiver enables a timer apparatus so that a medium cutting device will cut the recording medium at the proper place before and after the reproduced document to remove waste therefrom. In one embodiment a timer is provided in the transmitter to measure the time for the copy document to move from the copy inlet to the copy scanner and a separate timer is included in the receiver to measure the time for the recording medium to travel from the marking means to the paper cutter. In a second embodiment a timer is provided in the receiver which by itself measures the time required for the copy document at the transmitter to travel from the inlet to the scanner and the time required for the recording medium to go from the marking means to the cutter.

United States Patent [72] Inventors Joel C. Goldberg;

Dudley Gray, both of Chicago, Ill. [21] Appl. No. 712,165 [22] Filed Mar. 11, 1968 [45] Patented Oct. 19, 1971 [73] Assignee Stewart-Warner Corporation Chicago, Ill.

[54] ENABLING MEANS FOR A PAPER CUTTER IN A FACSIMILE SYSTEM 23 Claims, 8 Drawing Figs. [52] U.S. C1 178/6, 74/35, 83/203, 178/6.6 A [51] Int. Cl H04n l/02, F16h 35/12, B26d 5/26 [50] Field of Search 83/362, 203; l78/6.6, 6.6 A, 6 [56] References Cited UNITED STATES PATENTS 3,135,179 6/1964 Cerasani et al. 178/6.6 A 3,184,540 5/1965 Murphy 178/6 3,303,280 2/1967 Fox et a1. 178/6 3,479,451 11/1969 Regunberg 178/6.6

3,428,749 2/1969 Gray 3,169,432 2/1965 Hoffman ABSTRACT: Apparatus for severing recording medium in a document reproduction system, such as facsimile, wherein the transmitter produces an enabling signal indicating that a document has been inserted for reproduction and the detection of the signal at the receiver enables a timer apparatus so that a medium cutting device will cut the recording medium at the proper place before and after the reproduced document to remove waste therefrom. In one embodiment a timer is provided in the transmitter to measure the time for the copy document to move from the copy inlet to the copy scanner and a separate timer is included in the receiver to measure the time for the recording medium to travel from the marking means to the paper cutter In a second embodiment a timer is provided in the receiver which by itself measures the time required for the copy document at the transmitter to travel from the inlet to the scanner and the time required for the recording medium to go from the marking means to the cutter.

ENABLE TONE SIGNAL DET,

CUTTER CONTROL PATENTEDncT 19 I97! SHEET u 0F 5 F l G. 4.

INVENTOR'S Joan. c. GOLDBERG DUDLEY GRAY By Attorney ENABLING MEANS FOR A PAPER CUTTER IN A FACSIMILE SYSTEM This invention relates to recording medium severing apparatus in copy reproduction systems. Although the invention is described herein as it relates to facsimile systems in which graphic signals representative of a copy document to be reproduced are transmitted to a remotely located recorder for reproduction of the document on recording means, at least some of the features are applicable to medium severing apparatus for other copy reproduction systems.

Generally, a facsimile system comprises a transmitter at which means are provided to scan the document and produce signals which vary in accordance with the light intensity of the segment being scanned. A receiver at a remote location applies the varying signals to a recording means which produces marks on a recording medium such as an electrolytic paper in accordance with the document being scanned at the transmitter. The recording medium is ordinarily supplied from a roll in the recorder housing and is driven along a path through the marking means and out of the recorder. Although the recording medium is driven through the recorder in synchronism with the transportation of the copy document through the transmitter when the document is being scanned, there are occasions when the recording medium is being moved through the recorder when a document is not being reproduced. For example, in some systems at least the recorder is operated during the phasing period at the beginning of facsimile transmission responsive to phasing signals, and the recording medium is caused to move through the recorder even though the document at the transmitter is not yet being scanned. Excess paper is therefore transported through the marking means and out of the recorder before the receipt of graphic signals which reproduce the scanned document on the marking medium. In addition, unmarked portions of recording medium appear during the transmission of successive documents. Ordinary facsimile systems operate to continue the operation of the recording means during the period between successive documents so that blank spaces appear on the recording medium during the time between documents loaded into the transmitter.

It is the object of this invention to provide apparatus for automatically cutting the recording medium at the beginning and the end of each reproduced document so that the reproduction at the recorder will be of the same size as the document inserted at the transmitter with all excess medium from the leading and lagging edges removed. I

It is also an object of this invention to provide control apparatus for severing recording medium which is simple, easy to manufacture and inexpensive to maintain.

Another object of this invention is to provide control means associated with a copy document recording apparatus which is adapted to take into account any time delays required to sever the medium at the proper place with respect to the reproduced copy document.

A further object of this invention is to provide control apparatus for severing recording medium which includes means for disabling the severing means upon malfunction and operate an alarm.

It is also an object of this invention to provide an electromechanical timer of unique design for providing the required time delays in the recording medium severing system. The objects and advantages of this invention will be better understood upon a further reading of the specification especially when taken in view of the attached drawings in which:

F IG. 1 is a block diagram of one embodiment of a recording medium severing system as used with a facsimile transmission system;

FIG. 2 is a schematic diagram of the paper severing apparatus control circuits associated with the facsimile transmitter of the system shown in FIG. 1;

FIG. 3 is a schematic diagram of the recording medium severing apparatus control circuits associated with the facsimile receiver of the system shown in FIG. 1;

- FIG. 4 is a front elevation view of the electromechanical timer mechanism;

FIG. 5 is a section view of the timer mechanism taken along the lines 5-5 of FIG. 4;

FIG. 6 is an enlarged ball feed mechanism;

FIG. 7 is a partial rear view showing the drive means for the ball feed mechanism; and

FIG. 8 is a block diagram of another embodiment of a recording medium severing apparatus embodying the teachings of this invention.

The system shown in FIG. 1 includes a facsimile transmitter, referenced generally at 100, and a remotely located recorder, referenced generally at 102. The transmitter comprises scanning means 104 of any well known type in which a copy document 105 to be reproduced is insertable at an inlet 106 and driven by means of a drive roller 108 past a scanning slit 110. The document passing the slit 110 is scanned from side to side and signals are developed in the photocell 112 in acpartial view of the timer showing the cordance with the changes in reflected light intensity. These signals are prepared by the transmitter circuits 114 in preparation for transmission via telephone lines 116, or other appropriate media, to the remotely located recorder 102.

The transmitter 100 also includes control circuits which control the operation of the transmitter including the phasing period and the switch to video mode thereafter, for transmitting the document data. The operation of the transmitter control 120 is normally initiated by a copy document switch 122 which senses the insertion of a document to be reproduced. The copy document switch is located immediately adjacent the point at which the drive roller 108 begins driving the paper. Ordinarily it is also very close to the document inlet 106. The copy document switch 122 initiates the operation of the transmitter control 120 to provide a phasing period of perhaps 25 to 30 seconds. During this period phasing signals are sent through the transmitter circuits 114 and telephone lines 116 to the recorder 102 which are used to bring the recorder into synchronization with the transmitter. After the phasing period the transmitter control enables the transmitter circuits for video transmission of the document. The control 120 also energizes a copy drive motor 124 which by means of drive roller I08 starts the document towards the scanning slit 110. In some systems the document drive is started at the beginning of the phasing period, while in others it is started during or after the completion of the phasing period. As will be see the system shown herein is adapted to operate properly regardless of the start time of the document drive.

The facsimile recorder includes a receiver 126 which receives and separates the control and video signals from the transmitter. The video signals are handled by well known video circuits 130 and applied to appropriate marking apparatus 132 such as a rotatable helix electrode drum 134 and linear electrode 136. These two electrodes cooperate to mark the recording medium 138 passing therebetween from a supply roll 140. 1

The control signal detected by the receiver 126 are directed to a receiver control circuit 128. The receiver control 128 controls the energization of drive motor 142 which operates the marking means 132 and also provides the motive power for the recording medium by means of the drive roller 144.

When phasing signals are received from the transmitter at the beginning of document transmission, the receiver control causes the drive motor 142 to operate and synchronize itself with the passing signals so as to properly align the recorder 102 with the transmitter 100. At the end of the phasing period the receiver control then enables the video circuits 130 to pass the video signals to the marking means 132 to cause the reproduction of the document on the recording medium. Since the motor 142 is operated during the phasing period, it will be seen that a portion of unmarked recording medium passes the marking means 132 prior to the receipt of video signals. When the lagging edge of the copy document passes the'scanning slit 110, the transmitter control shuts down the transmitter if another document does not immediately succeed it. However, the receiver control usually continues the energization of the motor 142 for at least a short period of time to drive the document reproduction toward the receiver outlet.

The above brief description of the facsimile system contemplated the reproduction of a single document which required a phasing period prior to the transmission of the video signals representing the copy document being reproduced. Most facsimile systems also have provisions for automatic operation in which successive documents may be reproduced without requiring a phasing period in between if the succeeding documents follow one another into the copy inlet 106 of the transmitter within a predetermined time interval. The recording medium severing systems disclosed herein are designed to operate to remove the waste at the leading and lagging edges of the documentreproduction whether a single document or successive documents are being transmitted.

The recording medium severing apparatus in the system shown in FIG. 1 comprises a tone generator 146 which produces an enabling signal through an amplifier 148 and the transmitter circuits 114 to the recorder 102 when the leading edge and the lagging edge of the copy document reaches the scanning slit 110 in the scanning means 104. The tone generator 146 is controlled to produce the signal at the proper time by means of a time delay apparatus 150. The time delay apparatus 150 is designed to account for the time t 1 it takes for the document to reach the scanning slit 110 after the copy document drive roller 108 starts feeding it thereto. As previously discussed, this time period for the leading edge starts during or after the phasing period if another document had not immediately preceded it. If, however, the document is one of a succession of documents, but not the first document, the period t 1 starts by the operation of a copy feed switch 122 caused by the insertion of the leading edge of the document. Thus, when the document starts to be fed by the copy feed roller 108 towards the scanning slit 110 a time delay circuit 150 is energized. After time period I 1 representing the time for the document to reach the scanning slit 1 10, the time delay 150 causes the tone generator 146 to generate an enable signal for transmission to the recorder 102. Timer 152 limits the time length of the enable signal from the tone generator 146. When the lagging edge of the document reaches the copy feed switch 122 the time delay apparatus 150 is again energized. The tone generator 146 is caused thereby to produce another enable signal at a time interval 1', after the release of the copy feed switch 122, which represents the time for the lagging edge to travel to the scanning slit. 110. Thus, in the system of FIG. 1, an enable signal 1 is transmitted to the recorder at the time the leading edge of a copy document reaches the scanning slit and at the time the lagging edge reaches the scanning slit.

Associated with the recorder 102 is a recording medium severing device 154 such as an electrically controlled paper cutter of the type disclosed in the copending application of F.

' Thomas Bilek, Ser. No. 592,809, filed Nov. 8, 1966, now Pat.

No 3,465,632. Briefly, such a device comprises a set of cutter blades 1560, 156b, at least one of which is actuated by a motor drive means 158. The recording medium is drawn from the recorder and through the cutting apparatus by means of a separate drive roller 160 and motor 162.

The paper cutter device 154 is actuated by a cutter control circuit 164 which in turn is controlled by a memory timer 166. The operation of the memory timer is initiated when an enable signal is detected by a tone signal detector 168 after the enable signal has been processed by the receiver 126. The memory timer 166 delays the operation of the paper cutter device 154 for a time period t 2 after the receipt of the enable signal from the transmitter which represents the time for a portion of the recording medium 138 to pass from the marking means 132 to the cutter blades 156a, Gb. It will be recalled that in the system of FIG. 1 the enable signals are transmitted when the leading edge and the lagging edge of the copy document arrive at the scanning slit 110 in the transmitter. Thus, the portions of the paper at the marking means 132 when the enable signals are received represent the leading edge and lagging edge, respectively, of the reproduced document. Timer 166 delays the operation of the cutter device 154 until those portions of the recording medium reach the cutter blades so that the document may be accurately cut at its leading and lagging edges.

The memory timer 166 is constructed so that it can time a multiplicity of events simultaneously. Ordinarily it will take less than t 2 time to scan a copy document because of the physical distance between the marking means 132 and the paper cutter blades 156a and 1561:. Thus, the enabling signals for both the leading edge and the lagging edge will be sent to the recorder 102 before the paper cutting device 154 is actuated for the leading edge. The timer 166 must include a memory so that it can store and separately time the delay 7 period for the leading and lagging edges of the document. Furthermore, one or more succeeding documents may be inserted into the transmitter before the first document is cut. Provisions are therefore made in the timer for timing a multiplicity of events. The memory timer of the type described in detail later in the specification can time a substantial number of separate events so that a large number of succeeding documents can be controlled and cut with great accuracy.

Reference is now made to FIG. 2 in which schematic details of transmitter associated apparatus including the time delay 150, timer 152, tone generator 146 and amplifier 148 are shown. The t time delay circuit 150 comprises a silicon controlled rectifier 202 having its anode connected through a resistor 204 to a B+conductor 206 and its cathode connected directly to ground. The gate electrode of SCR 202 is connected to the base 1 electrode of a unijunction 208 across the output resistor 210. The base 2 electrode of the unijunction is connected to the B+conductor 206 through resistor 212. The emitter of the unijunction is connected to a timing circuit including capacitor 214 and a potentiometer 216 which may be manually controlled to set the desired 1 time interval.

Under normal conditions with power applied but no timing operation occurring, the SCR 202 is conducting so that essentially ground potential appears on the control conductor 218. The SCR 202 became conductive when power was first turned on in the following manner. Positive voltage is applied from terminal 220 through normally closed contacts 222aand 222k of a copy document relay 222 and normally closed contacts 2240, 224b of a document drive relay 224 to the B+conductor 206. When the positive voltage first appears on conductor 206 the capacitor 214 starts charging up through the potentiometer 216 until the emitter peak point voltage of the unijunction is reached to cause it to conduct. A positive voltage appears across resistor 210 and to the gate of SCR 202 to render it conductive. A diode 226 is connected between the time delay output conductor 218 and the emitter of unijunction 208 to stabilize the voltage level from which the capacitor 214 must The timer circuit 152 is similar to the circuit in the time delay 150 in that it'comprises a SCR 228 which is triggered into conduction by a unijunction 230. The anode of the SCR 228 is connected through a resistor 232 to a B+line 234 as is the B2 electrode of the unijunction230 through resistor 236. The cathode of SCR 228 is connected directly to a ground return line 229, and the base 1 electrode of the unijunction 230 is connected thereto through a load resistor 231. The gate of the electrode of the SCR 228 is connected to the base 1 electrode of unijunction 230 so that it is triggered into conduction when the unijunction 230 conducts. The emitter circuit of the unijunction 230 comprises a charging circuit including capacitor 238 and resistor 240 connected between the B+conductor 234 and the ground return line 229.

The tone generator 146 comprises a colpitts oscillator of ordinary design and hence need not be described in detail. However, its ground return line 242 is connected to the control conductor 218 from the time delay circuit 150 and its positive B+voltage is derived via conductor 244 from the anode circuit of the SCR 228 in the timer 152. The output from the tone generatorv is taken from the collector of the oscillator transistor 241 and applied to the input of a standard transistor amplifier circuit 148.

The timer circuit 152 and the tone generator 146 are maintained inoperable when the positive voltage is first turned on because of the lack of power to these circuits until the operation of the paper document feed relay 224. The copy docurnent feed relay 224 is connected to the normal transmitter control circuits 120 such that it actuates at the same time that the copy document drive motor 124 is actuated to start the travel of the document from the transmitter inlet towards the scanning slit 110 (FIG. 1). If the system is of the type that copy drive does not occur until sometime after the actuation of the copy document switch 122 by the insertion of a copy document, then the only thing that occurs at that time is a reset operation of the time delay circuit 150 by the momentary release of positive voltage from the B+line 206 at the copy feed relay contacts. Nothing occurs in the timer circuit 152 or the tone generator circuit 146 until the actuation of the copy document drive relay 224 when the document starts to travel towards the scanning slit.

it will be noted that the timer circuit 142 and the tone generator 146 have their respective ground return conductors 229 and 242 connected to ground via control conductor 218 only when the SCR 202 in the time delay circuit 150 is conducting. When the SCR 202 is nonconducting, conductor 218 and hence the ground return lines 229 and 242 are floating above ground.

When a document is inserted into the copy document inlet of the transmitter the actuation of the copy document switch 122 triggers the transmitter control 120 to begin the phasing period if another document had not immediately preceded it. Operation of the copy document switch 122 actuates the copy document relay 222 to move contact 222a from contact 22211 to its other contact 2220. The only efiect the operation of relay 222 has at this time is to momentarily interrupt the positive voltage on the B+line 206 which causes the time delay circuit 150 to reset itself. There is no effect on the timer circuit 152 and the tone generator 146 since positive voltage is withheld from these circuits by the open copy feed relay contacts 2240, 224d. When the transmitter control 120 actuates the document feed motor 124, relay 224 is actuated at the same time to provide positive voltage to these circuits. In addition, however, it momentarily interrupts the positive voltage on the B+conductor 206 as the contacts 224a goes from its normally closed contact 224b to the normally open contact 224e. This stops the conduction of the SCR .202 which is then held off until the unijunction timing circuit provides a gate pulse thereto. The unijunction 208 fires a time interval t, after the interruption of positive voltage on conductor 206 which is set by the potentiometer 216 equal to the time for the leading edge of the document to pass to the scanning slit 110.

Although positive voltage has been applied to the timer 152 and the tone generator 146 by the actuation of the copy feed relay 224, these circuits are not operative during the time delay SCR 202 is not conducting because of the absence ground on conductor 218 and hence the ground conductors 229 and 242 of the timer and tone generator circuits, respectively. However, as soon as the SCR 202 is gated into conduction after the time interval e,, ground is provided on conductor 218 and the tone generator oscillator begins to send out the enabling tone signal through the amplifier 148 and the transmitter circuits to the recorder. The appearance of ground on conductor 218 also causes the capacitor 238 in the timer circuit 152 to begin charging towards the peak emitter voltage of the unijunction 230 at a rate determined by the values of the capacitor 238 and resistor 240. -When the unijunction 230 fires, a positive gating signal is provided to the SCR 228 triggering it into conduction. This has the effect of removing the positive voltage from the B+conductor 224 of the tone generator 146 and stops the enable signal. Thus, an enabling signal of the tone generator oscillator frequency is transmitted to the recorder at a time corresponding to the arrival of the leading edge of the document at the scanning slit and it lasts for the time period determined by the timer circuit 152. In one constructed embodiment of the system of this invention an enabling signal of approximately 300 to 325 Hz. is used for a duration of approximately 400 milliseconds.

When the lagging edge of the document enters the copy inlet of the transmitter, the copy document switch 122 is released which deenergizes the copy document relay 222 and again momentarily interrupts the positive voltage on conductor 206. The time delay circuit 150 is reset causing the control ground line 218 to float above ground and disable the timer 152 and tone generator 146. After the time interval 1, representing the time for the lagging edge of the document to pass from the switch 122 at the copy inlet to the scanning slit 110, the tone generator 146 provides an enabling tone signal which lasts until the SCR 228 in the timer 152 begins to conduct.

Reference is now made to FIG. 3 for a detailed description of the circuits at the recorder for actuating the paper cutter. The enabling tone signal from the receiver 126 in the recorder 102 appears at terminal 302 where it is applied to the input of an emitter-follower amplifier circuit 304. The output therefrom is applied to common-collector transistor amplifier 306 which has in its output a resonant reed relay 308 tuned specifically to the enabling signal tone frequency. The vibrating contact 308a provides positive pulses to an integrating network comprising resistor 310 and capacitor 312. The time constant of the integrating network is established at about 125' milliseconds to insure that noise, signal dropout, or any other interference does not cause the following circuits to operate at the wrong time.

The voltage on integrating capacitor 312 feeds the input of a Schmidt trigger circuit 314 comprising a normally off transistor 316 and a nonnally on transistor 318. When the voltage on capacitor 312 reaches a sufiicient level, the

Schmidt trigger 314 is actuated and the high going voltage at the collector of transistor 318 causes transistor 320 to gointo conduction to charge capacitor 322 in its emitter circuit. This provides a voltage spike pulse across resistor 324 at the input of the drive transistor 326 causing it to momentarily go into saturated conduction through the circuit from ground through the emitter collector of transistor 326, conductor 328, and the actuating coil of a solenoid actuator 330 in the memory timer 166 to the DC power supply 333. g

The momentary actuation of solenoid 330 starts the operation of the memory timer 166 to measure the time interval 1, which, as previously explained, is the time interval required for a portion of the recording medium to travel from the recorder marking means 132 to the cutter blades 156a and b. Although the memory timer apparatus will be described in full detail later, it briefly comprises a rotatable threaded member 331 driven by a constant speed motor 332 energized by the ll7-volt AC voltage provided from the receiver control circuit 128 via conductors 334. The receiver control provides the ll7-volt AC only when the recorder 102 has been switched from its standby state to its receive state responsive to a signal from the transmitter 100. The memory timer 166 further comprises a supply of small elements or balls 336 which are injected into groove 338 axially aligned with the rotating member 331, responsive to the momentary actuation of the solenoid 330. A switch 340 is provided along the path of the ball as it is carried by the threads on the rotating member 331 so as to be actuated by the ball a time interval t, after injection into the groove 338.

Actuation of the switch 340 closes a circuit to a cutter actuator relay 342 extending from ground through the winding of relay 342, conductor 344, switch 340, conductor 346,

manual-automatic mode switch 348 to the DC power line 350 extending from the DC power supply 333. Energization of the relay 342 completes the circuit to the cutter motor 158 which drives the blades 1560, 156!) through a circuit from AC power terminal 352, fuse 354, interlock switch 356, conductor 358, normally open contacts 342a of the cutter control relay, conductor 360, cutter motor 358, conductor 361, normally closed contacts 362a of an alann timer relay 362, power switch 363 and a fuse 364 to the other AC power terminal 352a.

When the cutter motor 158 moves the cutter blades 156a, 156b from their at-rest position, a blade limit switch 365 is actuated to provide a hold circuit by means of the closure of contacts 365a around the cutter control relay contact 342a. Thus, the cutter can continue through its cycle even though the cutter control relay 342 is only momentarily actuated by the ball switch 340 in the memory timer 166.

At the same time that the cutter motor 158 is actuated a paper drive stop relay 366 is actuated to open contacts 366a in the power circuit for the paper drive motor 152 (FIG. 1) in the paper severing apparatus 154. Thus, a smooth linear cut is made across the paper in the manner described in detail in the aforementioned Bilek application.

The blade limit switch 365 has another set of contacts 365b which serve to control an alarm circuit 366 within the cutter control. The alarm circuit 366 comprises a silicon controlled rectifier and unijunction timer circuit much like those used for the time delay 150 and timer 152 in the transmitter. When the cutter blades are not operating and the blade limit switch 365 is in its normal state, ground is present on the B+conductor 368 for the unijunction 370 and SCR 372. They are of course nonconducting as is the alarm relay 362 which has its actuating winding connected between the B-l-conductor 368 and the anode of the SCR 372. As soon as the cutter blades begin to operate and actuate the blade limit switch 365 to its other condition, positive voltage is provided through contacts 365b to the B-hconductor 368, and capacitor 374 in the emitter circuit of the unijunction 370 begins to charge up through resistor 376. The component values of capacitor 374 and resistor 376 are chosen so that the capacitor will not be able to charge to the peak emitter voltage of the unijunction 370 during the normal operating time of the cutter blades. Thus, under ordinary circumstances the return of the cutter blades to their athome position will cause the blade limit switch 365 to remove positive voltage from the 8+ conductor 368 before the unijunction 370 tires and gates the SCR 372 into conduction. If, however, the blades get jammed at a position other than the at-home position, the continual positive voltage on conductor 368 will cause the unijunction 370 to fire and gate the SCR 372 into conduction. The alarm relay 362 is actuated by the flow of the current from the B+ conductor 368 through the winding of relay 362 and the SCR 372 to ground, thus actuating its contacts in the power circuit for the cutter motor 158. Power is cut off to the cutter motor by the opening'of contacts 362a and is applied to a buzzer 378 by the closure of contacts 3621: to provide an audible alarm to the operator that a malfunction has occurred.

The circuits at the recorder thus operate to actuate the cutter blades 156a, 156b a time interval after the receipt of an enable signal. The time t, is measured by the memory timer I66 and equals the time for the paper to move from the recorder marking means 132 to the cutter blades. The particular memory time 166 disclosed herein and shown in detail in FIGS. 4-7 is especially useful because it enables the timing of several events at the same time as might be required for the leading and lagging edges of one or more documents which might have a total length less than the length of the paper extending from the marking means 132 to the paper cutter blades 156a, 156k.

The memory timer 166 as shown in FIGS. 4 through 7 comprises a body member 400 formed of a solid rectangular cross sectional shaped bar stock having a shoulder 402 out along one edge thereof. A cover 404, preferably but not necessarily of transparent material, is secured to the surface of the body 400 and extends beyond the shoulder 402 to form therewith the groove or chamber 338 along which the ball elements 336 travel. The thread bearing rotatable member 331 is joumaled for rotation adjacent the groove 338 in a pair of support brackets 406, 408. The member 331 is driven by the constant speed motor 332 through an appropriate gear drive 410. I

A supply of balls 336 are contained in another groove 412 formed in the surface of the body member 400 which cooperates with the cover 404 to form a return passageway extending from the top of groove 338 to the insertion means 414. Enough balls are contained in the upward slanting portion 413 of the passageway for timing the maximum expected number of events. 7

The ball insertion means 414 comprises an arm 416 secured to a pin 418 extending through and rotatable within the body member 400. The am 416 is rotatable from the position shown by dark lines in FIG. 6 to the position shown by the dotted lines 416'. It has a recess 420 at its upper edge which receives a single ball 336 when it is in its position 416 and deposits it in the groove 338 as it moves to its position 416. Y

The threads on the rotating member 331 then carry the inserted ball 336 upward along the groove 338 while the nonrecessed portion of the top of the arm 416 prevents any further balls from being inserted until the arm 416 is again actuated. The switch 340 which is actuatable by a ball 336 traveling along the groove 338 is mounted therealong at a position such that it takes a time interval r, to travel from its insertion point to the switch 340.

The arm 416 is actuated by the solenoid actuator 330 (FIG. 7) which pulls its plunger 422 in the direction of arrow 424 when energized. The linear movement of the plunger 422 is transformed into a rotatable movement of the pin 418 by means of a linkage member 426 loosely attached at one end to the plunger 422 and keyed to the pin 418 carrying the insertion arm 416.

The memory timer 156 described herein is a simply fabricated device which can time a multiplicity of separate events since a great number of balls 336 can travel within the groove 338 at one time. Each ball represents an event which is timed from its insertion until it actuates the switch 340. It is to be noted that the time t, may be adjusted in a number of different ways. For example, the position of the switch'340 may be moved to any point along the threaded member 331 for any desired time interval. In addition, the motor 322 and/or gear train 410 may be changed to change the speed of rotation of the threaded member 331 and hence the length of time inter- Val 12.

The timer mechanism'described may also be used in the recording medium severing system shown in block diagram in FIG. 8. In this system the apparatus at the recorder 102 can be substantially the same as that described for the embodiment of FIG. 1 except that the memory timer 166 provides a time delay equal to t, +t t being the time for the copy document to be driven to the scanning slit I10 and t, being the time for the recording medium to travel from the marking means to the paper cutter blades.

The transmitter in this case, however, must transmit the enable signal when the document starts to be driven towards the scanning slit 110. Therefore, there is no time delay in the transmitter apparatus, and the copy document switch 122 triggers the enable signal generator 146 to provide the enable signal through the transmitter circuits I14 and the phone lines 118 to the remote recorder 102. In this case, however, the lagging edge of a document will normally pass the copy document switch 122 at a time when a portion of the document is being scanned at the scanning slit 110..In order to prevent distortion of the video signals it is necessary to limit the generation of the enable signal to the blanking period between lines of the scanned document. This can be controlled by simple means well known in the art coupled to the scanner. For example, a segmented commutator can be used with the well known rotating type of facsimile scanners to permit the transmission of the enabling signal to the period in between scanned lines.

While there has been described herein detailed embodiments having the features of this invention, it is to be understood that many additions and/or modifications may be made thereto without materially deviating from the teachings herein. It is therefore intended to be limited only by the scope of the appended claims.

What is claimed is:

1. For use in a facsimile system having a facsimile transmitter and a facsimile recorder, said transmitter including means for scanning a copy document, a copy document inlet, means for driving the copy document from the inlet to the scanning means and means for producing video signals in accordance with the scanned copy document, said facsimile recorder including a recording medium supply, means for marking the medium in accordance with received video signals from the transmitter and means for driving the medium along a path through the marking means to reproduce the copy document thereon; a system for severing the recording medium comprising means at said transmitter for providing an enabling signal when an edge of said copy document reaches the scanning means, meansat said recorder for detecting said enabling signal, means for severing said medium downstream of said marking means, and a timer operable by said detecting means for operating said severing means a predetermined time interval after said enabling signal approximating the time required for said recording medium to pass from said marking means to said severing means whereby said medium is severed at a place on the reproduced copy document corresponding to an edge of said copy document, said enabling signal providing means comprising an oscillator for providing a tone signal and said detecting means comprising a vibrating reed switch operable at said tone signal frequency.

2. For use in a facsimile system having a facsimile transmitter and a facsimile recorder, said transmitter including means for scanning a copy document, a copy document inlet, means for driving the copy document from the inlet to the scanning means for producing video signals in accordance with the scanned copy document, said facsimile recorder including a recording medium supply, means for making the medium in accordance with received video signals from the transmitter and means for driving the medium along a path through the marking means to reproduce the copy document thereon; a system for severing the recording medium comprising means at said transmitter for providing an enabling signal when an edge of said copy document reaches the scanning means, means at said recorder for detecting said enabling signal, means for severing said medium downstream of said marking means, and a timer operable by said detecting means for operating said severing means a predetermined time interval after said enabling signal approximating the time required for said recording medium to pass from said marking means to said severing means whereby said medium is severed at a place on the reproduced copy document corresponding to an edge of said copy document, said severing means comprising a pair of cutter blades through which said medium passes, a motor operable by said operating means for actuating said cutter blades and means operative responsive to the malfunctioning of said cutter blades for disabling said motor and producing an alarm.

3. For use in a facsimile system having a facsimile transmitter and a facsimile recorder, said transmitter including means for scanning a copy document, a copy document inlet, meansfor driving the copy document from the inlet to the scanning means and means for producing video signals in ac cordance with the scanned copy document, said facsimile recorder including a recording medium supply, means for marking the medium in accordance with received video signals from the transmitter and means for driving the medium along a path through the marking means to reproduce the copy document thereon; a system for severing the recording medium comprising means at said transmitter for providing an enabling signal when an edge of said copy document reaches the scanning means, means at said recorder for detecting said enabling signal, means for severing said medium downstream of said marking means, and a timer operable by said detecting means for operating said severing means a predetermined time interval after said enabling signal approximating the time required for said recording medium to pass from said marking means to said severing means whereby said medium is severed at a place on the reproduced copy document corresponding to an edge of said copy document, said severing means comprising a pair of cutter blades through which said medium passes, a motor operable by said operating means for actuating said cutter blades and means for driving said medium from said marking means to said cutter blades, and means for disabling said last mentioned driving means when said cutter blades are actuated.

4. A facsimile system comprising a facsimile transmitter and a facsimile recorder, said transmitter comprising means for scanning a document from one end to the other end and means for providing video signals in accordance with the scanned copy document, said facsimile recorder comprising a recording medium supply, means for marking the medium in accordance with received video signals from the transmitter and means for driving the medium along a path through the marking'means to reproduce the copy document thereon, and a system for severing the recording medium, said severing system comprising means in said transmitter for providing an enabling signal when an end of said copy document is scanned, means at said recorder for detecting said enabling signal, means for severing said medium downstream of said marking means, and a timer operable responsive to said detecting means for operating said severing means a predetermined time interval after said enabling signal approximating the time required for said recording medium to pass from said marking means to said severing means whereby said medium is severed at a place on the reproduced copy document corresponding to an end of said copy document, said timer comprising means defining a first groove, means defining a second groove for cooperation with the first groove to define a chamber therebetween, means for effecting movement of one groove with respect to the other to cause said chamber to move along a path at a predetermined velocity, an element adapted to be carried in said chamber, means for introducing said element into said chamber to mark the beginning of a predetennined interval responsive to said enabling signal, and means along said path for detecting the passage of said element to actuate said severing means, said enabling signalv providing means comprising an oscillator for providing a tone signal and said detecting means comprises a vibrating reed switch operable at said tone signal frequency.

5. For use in a document reproduction system having means for scanning a copy document from a starting edge to a finishing edge, a substantially continuous supply of recording medium, means responsive to said scanning means for marking said recording medium in replication of said copy document, and means for driving said recording medium along a path through said marking means; a system for severing said medium comprising means for severing said recording medium, means for detecting the scanning of said starting and finishing edges, and a timer for operating said severing means a predetermined time interval after the detection of each edge scanning, said time interval approximating the time required for said recording medium to pass from said marking means to said severing means, said severing means comprising a pair of cutter blades through which said medium passes, a motor operable by said operating means for actuating said cutter blades and means operative responsive to the malfunctioning of said cutter blades for disabling said motor and producing an alarm.

6. For use in a document reproduction system having means for scanning a copy document from a starting edge to a finishing edge, a substantially continuous supply of recording mediurn, means responsive to said scanning means for marking said recording medium in replication of said copy document, and

means for driving said recording medium along a path through said marking means; a system for severing said medium comprising means for severing said recording medium, means for detecting the scanning of said starting and finishing edges, and a timer for operating said severing means a predetermined time interval after the detection of each edge scanning, said time interval approximating the time required for said recording medium to pass from said marking means to said severing means, said severing means comprising a pair of cutter blades through which said medium passes, a motor operable by said operating means for actuating said cutter blades, means for driving said medium from said marking means to said cutter blades, and means for disabling said last mentioned driving means when said cutter blades are actuated.

7. A document reproduction system comprising means for scanning a copy document, a substantially continuous supply of recording medium, means responsive to said scanning means for marking said recording medium in replication of said copy document, means for driving said recording medium along a path through said marking means, means for severing said recording medium downstream of said marking means, means indicative of the start and finish of the document scanning for providing a enabling signal, and a timer for operating said severing means a predetermined time interval after said enabling signal, said time interval approximating the time required for said recording medium to pass from said marking means to said severing means, said timer comprising means defining a first groove, means defining a second groove for cooperation with the first groove to define-a chamber therebetween, means for effecting movement of one groove with respect to the other to cause said chamber to move along a path at a predetermined velocity, an element adapted to be carried in said chamber, means for introducing said element into said chamber to mark the beginning of a predetermined interval responsive to said enabling signal, and means along said path for detecting the passage of said element to actuate said severing means.

8. For use in a facsimile system having a facsimile transmitter and a facsimile recorder, said transmitter including means for scanning a copy document, a copy document inlet, means for driving the copy document from the inlet to the scanning means and means for producing video signals in accordance with the scanned copy document, said facsimile recorder including a recording medium supply, means for marking the medium in accordance with received video signals from the transmitter and means for driving the medium along a path through the marking means to reproduce the copy document thereon; a system for severing the recording medium comprising means at said transmitter for providing an enabling signal when an edge of said copy document reaches the scanning means, means at said recorder for detecting said enabling signal, means for severing said medium downstream of said marking means, and a timer operable by said detecting means for operating said severing means a predetermined time interval after said enabling signal approximating the time required for said recording medium to pass from said marking means to said severing means whereby said medium is severed at a place on the reproduced copy document corresponding to an edge of said copy document, said timer comprising means defining a first groove, means defining a second groove for cooperation with the first groove to define a chamber therebetween, means for effecting movement of one groove with respect to the other to cause said chamber to move along a path at a predetermined velocity, an element adapted to be carried in said chamber, means for introducing said element into said chamber to mark the beginning of a predetermined interval responsive to said enabling signal, and means along said path for detecting the passage of said element to actuate said severing means.

9. In the system of claim 8 wherein said first groove defining means comprises a substantially cylindrical member having a spiral groove around its periphery, wherein said second groove extends in a substantially axial direction with respect to said spiral, and wherein said movement efi'ecting means comprises means for rotating one of said groove defining means with respect to the other about the axis of said spiral groove.

10. In the system of claim 8 wherein said timer comprises a plurality of said elements and means defining a return path for said elements from said groove at a position beyond said switch to said introducing means.

11. In the system of claim 8 wherein said enabling signal providing means comprises means for sensing the insertion of a copy document into said inlet, and means operable by said sensing means for providing said enabling signal a predetermined time interval after document insertion approximating the time required for a portion of said copy document to pass from said inlet to said scanning means.

12. In the system of claim 11 wherein said enabling signal providing means comprises an oscillator for providing a tone signal, a first timing means operable by said sensing means to start said oscillator and a second timing means for stopping said oscillator a predetermined time after starting.

13. In the system of claim 8 wherein said enabling signal providing means comprises means for sensing the insertion of a copy document into said inlet, and means operable by said sensing means for providing said enabling signal a predetermined time interval after document insertion approximating the time required for a portion of said copy document to pass from said inlet to said scanning means.

14. In the system of claim 13 wherein said enabling signal providing means comprises an oscillator for providing a tone signal, a first timing means operable by said sensing means to start said oscillator and a second timing means for stopping said oscillator a predetermined time after starting.

15. A facsimile system comprising a facsimile transmitter and a facsimile recorder, said transmitter comprising means for scanning a document from one end to the other and means for producing video signals in accordance with the scanned copy document, said facsimile recorder comprising a recording medium supply, means for marking the medium in accordance with received video signals from the transmitter-and means for driving the medium along a path through the marking means to reproduce the copy document thereon, and a system for severing the recording medium, said severing system comprising means in said transmitter for providing an enabling signal when an end of said copy document is scanned, means at said recorder for detecting said enabling signal, means for severing said medium downstream of said marking means, and a timer operable responsive to said detecting means for operating said severing means a predetermined timer interval after said enabling signal approximating the time required for said recording medium to pass from said marking means to said severing means whereby said medium is severed at a place on the reproduced copy document corresponding to an end of said copy document, said timer comprising means defining a first groove, means defining a second groove for cooperation with the first groove to define a chamber therebetween, means for effecting movement of one groove with respect to the other to cause said chamber to move along a path at a predetermined velocity, an element adapted to be carried in said chamber, means for introducing said element into said chamber to mark the beginning of a predetermined interval responsive to said enabling signal, and means along said path for detecting the passage of said element to actuate said severing means.

16. In the system of claim 15 wherein said first groove defining means comprises a substantially cylindrical member having a spiral groove around its periphery, wherein said second groove extends in a substantially axial direction with respect to said spiral, and wherein said movement efiecting means comprises means for rotating one of said groove defining means with respect to the other about the axis of said spiral groove.

17. In the system of claim 16 wherein said timer comprises a plurality of said elements and means defining a return path for said elements from said groove at a position beyond said switch to said introducing means.

18. For use in a facsimile system having a facsimile transmitter and a facsimile recorder, said transmitter including means for scanning a copy document, a copy document inlet,

means for driving the copy document from the inlet to the scanning means and means for producing video signals in accordance with the scanned copy document, said facsimile recorder including a recording medium supply, means for marking the medium in accordance with received video signals from the transmitter and means for driving the medium along a path through the marking means to reproduce the copy document thereon; a system for severing the recording medium comprising means for severing said medium downstream of said marking means, means for sensing the passage of a document edge through said copy inlet, and timing means initiatable by said sensing means for operating said severing means a predetermined time interval after the sensing of said document edge approximating the time required for the passage of said document from said inlet 'to said scanning means plus the time required for said recording medium to pass from said marking means to said severing means, said timer comprising means defining a first groove, means defining a second groove for cooperation with the first groove to define a chamber therebetween, means for efiecting movement of one groove with respect to the other to cause said chamber to move along a path at a predetermined velocity, an element adapted to be carried in said chamber, means for introducing said element into said chamber to mark the beginning of a predetermined interval responsive to said enabling signal, and means along said path for detecting the passage of said element to actuate said severing means.

19. In the system of claim 18 wherein said timing means comprises means operable by said sensing means for providing an enabling signal a predetermined time interval after document insertion approximating the time required for an edge of said copy document to pass from said inlet to said scanning means, and means actuatable by said enabling signal for operating said severing means a predetermined time interval after said enabling signal approximating the time required for said medium to pass from said marking means to said severing means.

20. in the system of claim 18 wherein said timing means comprises means for providing an enabling signal when a document edge is sensed by said sensing means, and means actuatable by said enabling signal for operating said severing means said predetermined time interval after said enabling signal.

21. For use in a document reproduction system having means for scanning a copy document from a starting edge to a finishing edge, a substantially continuous supply of recording medium, means responsive to said scanning means for marking said recording medium in replication of said copy document, and means for driving said recording medium along a path through said marking means; a system for severing said medium comprising means for severing said recording medium, means for detecting the scanning of said starting and finishing edges, and a timer for operating said severing means a predetermined time interval after the detection of each edge scanning, said time interval approximating the time required for said recording medium to pass from said marking means to said severing mean said timer comprising means defining a first groove, means defining a second groove for cooperation with the first groove to define a chamber therebetween, means for effecting movement of one groove with respect to the other to cause said chamber to move along a path at a predetermined velocity, an element adapted to be carried in said chamber, means for introducing said element into said chamber to mark the beginning of a predetermined interval responsive to said enabling signal, and means along said path for detecting the passage of said element to actuate said severing means.

22. In the system of claim 21 wherein said first groove defining means comprises a substantially cylindrical member hav ing a spiral groove around its periphery, wherein said second groove extends in a substantially axial direction with respect to said spiral, and wherein said movement effecting means comprises means for rotatin one of said groove defining means with respect to the ot er about the axis of said spira groove.

23. In the system of claim 22 wherein said timer comprises a plurality of said elements and means defining a return path for said elements from said groove at a position beyond said switch to said introducing means. 

1. For use in a facsimile system having a facsimile transmitter and a facsimile recorder, said transmitter including means for scanning a copy document, a copy document inlet, means for driving the copy document from the inlet to the scanning means and means for producing video signals in accordance with the scanned copy document, said facsimile recorder including a recording medium supply, means for marking the medium in accordance with received video signals from the transmitter and means for driving the medium along a path through the marking means to reproduce the copy document thereon; a system for severing the recording medium comprising means at said transmitter for providing an enabling signal when an edge of said copy document reaches the scanning means, means at said recorder for detecting said enabling signal, means for severing said medium downstream of said marking means, and a timer operable by said detecting means for operating said severing means a predetermined time interval after said enabling signal approximating the time required for said recording medium to pass from said marking means to said severing means whereby said medium is severed at a place on the reproduced copy document corresponding to an edge of said copy document, said enabling signal providing means comprising an oscillator for providing a tone signal and said detecting means comprising a vibrating reed switch operable at said tone signal frequency.
 2. For use in a facsimile system having a facsimile transmitter and a facsimile recorder, said transmitter including means for scanning a copy document, a copy document inlet, means for driving the copy document from the inlet to the scanning means for producing video signals in accordance with the scanned copy document, said facsimile recorder including a recording medium supply, means for making the medium in accordance with received video signals from the transmitter and means for driving the medium along a path through the marking means to reproduce the copy document thereon; a system for severing the recording medium comprising means at said transmitter for providing an enabling signal when an edge of said copy document reaches the scanning means, means at said recorder for detecting said enabling signal, means for severing said medium downstream of said marking means, and a timer operable by said detecting means for operating said severing means a predetermined time interval after said enabling signal approximating the time required for said recording medium to pass from said marking means to said severing means whereby said medium is severed at a place on the reproduced copy document corresponding to an edge of said copy document, said severing means comprising a pair of cutter blades through which said medium passes, a motor operable by said operating means for actuating said cutter blades and means operative responsive to the malfunctioning of said cutter blades for disabling said motor and producing an alarm.
 3. For use in a facsimile system having a facsimile transmitter and a facsimile recorder, said transmitter including means for scanning a copy document, a copy document inlet, means for driving the copy document from the inlet to the scanning means and means for producing video signals in accordance with the scanned copy document, said facsimile recorder including a recording medium supply, means for marking the medium in accordance with received video signals from the transmitter and means for driving the medium along a path through the marking means to reproduce the copy document thereon; a system for severing the recording medium comprising means at said transmitter for providing an enabling signal when an edge of said copy document reaches the scanning means, means at said recorder for detecting said enabling signal, means for severing said medium downstream of said marking means, and a timer operable by said detecting means for operating said severing means a predetermined time interval after said enabling signal approximating the time required for said recording medium to pass from said marking means to said severing means whereby said medium is severed at a place on the reproduced copy document corresponding to an edge of said copy document, said severing means comprising a pair of cutter blades through which said medium passes, a motor operable by said operating means for actuating said cutter blades and means for driving said medium from said marking means to said cutter blades, and means for disabling said last mentioned driving means when said cutter blades are actuated.
 4. A facsimile system comprising a facsimile transmitter and a facsimile recorder, said transmitter comprising means for scanning a document from one end to the other end and means for providing video signals in accordance with the scanned copy document, said facsimile recorder comprising a recording medium supply, means for marking the medium in accordance with received video signals from the transmitter and means for driving the medium along a path through the marking means to reproduce the copy document thereon, and a system for severing the recording medium, said severing system comprising means in said transmitter for providing an enabling signal when an end of said copy document is scanned, means at said recorder for detecting said enabling signal, means for severing said medium downstream of said marking means, and a timer operable responsive to said detecting means for operating said severing means a predetermined time interval after said enabling signal approximating the time required for said recording medium to pass from said marking means to said severing means whereby said medium is severed at a place on the reproduced copy document corresponding to an end of said copy document, said timer comprising means defining a first groove, means defining a second groove for cooperation with the first groove to define a chamber therebetween, means for effecting movement of one groove with respect to the other to cause said chamber to move along a path at a predetermined velocity, an element adapted to be carried in said chamber, means for introducing said element into said chamber to mark the beginning of a predetermined interval responsive to said enabling signal, and means along said path for detecting the passage of said element to actuate said severing means, said enabling signal providing means comprising an oscillator for providing a tone signal and said detecting means comprises a vibrating reed switch operable at said tone signal frequency.
 5. For use in a document reproduction system having means for scanning a copy document from a starting edge to a finishing edge, a substantially continuous supply of recording medium, means responsive to said scanning means for marking said recording medium in replication of said copy document, and means for driving said recording medium along a path through said marking means; a system for severing said medium comprising means for severing said recording medium, means for detecting the scanning of said starting and finishing edges, and a timer for operating said severing means a predetermined time interval after the detection of each edge scanning, said time interval approximating the time required for said recording medium to pass from said marking means to said severing means, said severing means comprising a pair of cutter blades through which said medium pAsses, a motor operable by said operating means for actuating said cutter blades and means operative responsive to the malfunctioning of said cutter blades for disabling said motor and producing an alarm.
 6. For use in a document reproduction system having means for scanning a copy document from a starting edge to a finishing edge, a substantially continuous supply of recording medium, means responsive to said scanning means for marking said recording medium in replication of said copy document, and means for driving said recording medium along a path through said marking means; a system for severing said medium comprising means for severing said recording medium, means for detecting the scanning of said starting and finishing edges, and a timer for operating said severing means a predetermined time interval after the detection of each edge scanning, said time interval approximating the time required for said recording medium to pass from said marking means to said severing means, said severing means comprising a pair of cutter blades through which said medium passes, a motor operable by said operating means for actuating said cutter blades, means for driving said medium from said marking means to said cutter blades, and means for disabling said last mentioned driving means when said cutter blades are actuated.
 7. A document reproduction system comprising means for scanning a copy document, a substantially continuous supply of recording medium, means responsive to said scanning means for marking said recording medium in replication of said copy document, means for driving said recording medium along a path through said marking means, means for severing said recording medium downstream of said marking means, means indicative of the start and finish of the document scanning for providing a enabling signal, and a timer for operating said severing means a predetermined time interval after said enabling signal, said time interval approximating the time required for said recording medium to pass from said marking means to said severing means, said timer comprising means defining a first groove, means defining a second groove for cooperation with the first groove to define a chamber therebetween, means for effecting movement of one groove with respect to the other to cause said chamber to move along a path at a predetermined velocity, an element adapted to be carried in said chamber, means for introducing said element into said chamber to mark the beginning of a predetermined interval responsive to said enabling signal, and means along said path for detecting the passage of said element to actuate said severing means.
 8. For use in a facsimile system having a facsimile transmitter and a facsimile recorder, said transmitter including means for scanning a copy document, a copy document inlet, means for driving the copy document from the inlet to the scanning means and means for producing video signals in accordance with the scanned copy document, said facsimile recorder including a recording medium supply, means for marking the medium in accordance with received video signals from the transmitter and means for driving the medium along a path through the marking means to reproduce the copy document thereon; a system for severing the recording medium comprising means at said transmitter for providing an enabling signal when an edge of said copy document reaches the scanning means, means at said recorder for detecting said enabling signal, means for severing said medium downstream of said marking means, and a timer operable by said detecting means for operating said severing means a predetermined time interval after said enabling signal approximating the time required for said recording medium to pass from said marking means to said severing means whereby said medium is severed at a place on the reproduced copy document corresponding to an edge of said copy document, said timer comprising means defining a first groove, means defining a second groove for cooperation with the first grooVe to define a chamber therebetween, means for effecting movement of one groove with respect to the other to cause said chamber to move along a path at a predetermined velocity, an element adapted to be carried in said chamber, means for introducing said element into said chamber to mark the beginning of a predetermined interval responsive to said enabling signal, and means along said path for detecting the passage of said element to actuate said severing means.
 9. In the system of claim 8 wherein said first groove defining means comprises a substantially cylindrical member having a spiral groove around its periphery, wherein said second groove extends in a substantially axial direction with respect to said spiral, and wherein said movement effecting means comprises means for rotating one of said groove defining means with respect to the other about the axis of said spiral groove.
 10. In the system of claim 8 wherein said timer comprises a plurality of said elements and means defining a return path for said elements from said groove at a position beyond said switch to said introducing means.
 11. In the system of claim 8 wherein said enabling signal providing means comprises means for sensing the insertion of a copy document into said inlet, and means operable by said sensing means for providing said enabling signal a predetermined time interval after document insertion approximating the time required for a portion of said copy document to pass from said inlet to said scanning means.
 12. In the system of claim 11 wherein said enabling signal providing means comprises an oscillator for providing a tone signal, a first timing means operable by said sensing means to start said oscillator and a second timing means for stopping said oscillator a predetermined time after starting.
 13. In the system of claim 8 wherein said enabling signal providing means comprises means for sensing the insertion of a copy document into said inlet, and means operable by said sensing means for providing said enabling signal a predetermined time interval after document insertion approximating the time required for a portion of said copy document to pass from said inlet to said scanning means.
 14. In the system of claim 13 wherein said enabling signal providing means comprises an oscillator for providing a tone signal, a first timing means operable by said sensing means to start said oscillator and a second timing means for stopping said oscillator a predetermined time after starting.
 15. A facsimile system comprising a facsimile transmitter and a facsimile recorder, said transmitter comprising means for scanning a document from one end to the other and means for producing video signals in accordance with the scanned copy document, said facsimile recorder comprising a recording medium supply, means for marking the medium in accordance with received video signals from the transmitter and means for driving the medium along a path through the marking means to reproduce the copy document thereon, and a system for severing the recording medium, said severing system comprising means in said transmitter for providing an enabling signal when an end of said copy document is scanned, means at said recorder for detecting said enabling signal, means for severing said medium downstream of said marking means, and a timer operable responsive to said detecting means for operating said severing means a predetermined timer interval after said enabling signal approximating the time required for said recording medium to pass from said marking means to said severing means whereby said medium is severed at a place on the reproduced copy document corresponding to an end of said copy document, said timer comprising means defining a first groove, means defining a second groove for cooperation with the first groove to define a chamber therebetween, means for effecting movement of one groove with respect to the other to cause said chamber to move along a path at a predetermined velocity, an element adapted to be carried in said chamber, means for introducing said element into said chamber to mark the beginning of a predetermined interval responsive to said enabling signal, and means along said path for detecting the passage of said element to actuate said severing means.
 16. In the system of claim 15 wherein said first groove defining means comprises a substantially cylindrical member having a spiral groove around its periphery, wherein said second groove extends in a substantially axial direction with respect to said spiral, and wherein said movement effecting means comprises means for rotating one of said groove defining means with respect to the other about the axis of said spiral groove.
 17. In the system of claim 16 wherein said timer comprises a plurality of said elements and means defining a return path for said elements from said groove at a position beyond said switch to said introducing means.
 18. For use in a facsimile system having a facsimile transmitter and a facsimile recorder, said transmitter including means for scanning a copy document, a copy document inlet, means for driving the copy document from the inlet to the scanning means and means for producing video signals in accordance with the scanned copy document, said facsimile recorder including a recording medium supply, means for marking the medium in accordance with received video signals from the transmitter and means for driving the medium along a path through the marking means to reproduce the copy document thereon; a system for severing the recording medium comprising means for severing said medium downstream of said marking means, means for sensing the passage of a document edge through said copy inlet, and timing means initiatable by said sensing means for operating said severing means a predetermined time interval after the sensing of said document edge approximating the time required for the passage of said document from said inlet to said scanning means plus the time required for said recording medium to pass from said marking means to said severing means, said timer comprising means defining a first groove, means defining a second groove for cooperation with the first groove to define a chamber therebetween, means for effecting movement of one groove with respect to the other to cause said chamber to move along a path at a predetermined velocity, an element adapted to be carried in said chamber, means for introducing said element into said chamber to mark the beginning of a predetermined interval responsive to said enabling signal, and means along said path for detecting the passage of said element to actuate said severing means.
 19. In the system of claim 18 wherein said timing means comprises means operable by said sensing means for providing an enabling signal a predetermined time interval after document insertion approximating the time required for an edge of said copy document to pass from said inlet to said scanning means, and means actuatable by said enabling signal for operating said severing means a predetermined time interval after said enabling signal approximating the time required for said medium to pass from said marking means to said severing means.
 20. In the system of claim 18 wherein said timing means comprises means for providing an enabling signal when a document edge is sensed by said sensing means, and means actuatable by said enabling signal for operating said severing means said predetermined time interval after said enabling signal.
 21. For use in a document reproduction system having means for scanning a copy document from a starting edge to a finishing edge, a substantially continuous supply of recording medium, means responsive to said scanning means for marking said recording medium in replication of said copy document, and means for driving said recording medium along a path through said marking means; a system for severing said medium comprising means for severing said recording medium, means for detecting the scanning of said starting and finishing edges, and a timer for operating said severing means a predetermined time interval after the detection of each edge scanning, said time interval approximating the time required for said recording medium to pass from said marking means to said severing mean said timer comprising means defining a first groove, means defining a second groove for cooperation with the first groove to define a chamber therebetween, means for effecting movement of one groove with respect to the other to cause said chamber to move along a path at a predetermined velocity, an element adapted to be carried in said chamber, means for introducing said element into said chamber to mark the beginning of a predetermined interval responsive to said enabling signal, and means along said path for detecting the passage of said element to actuate said severing means.
 22. In the system of claim 21 wherein said first groove defining means comprises a substantially cylindrical member having a spiral groove around its periphery, wherein said second groove extends in a substantially axial direction with respect to said spiral, and wherein said movement effecting means comprises means for rotating one of said groove defining means with respect to the other about the axis of said spiral groove.
 23. In the system of claim 22 wherein said timer comprises a plurality of said elements and means defining a return path for said elements from said groove at a position beyond said switch to said introducing means. 